The approaches described in this section could be pursued but are not necessarily approaches that have previously been conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section.
A typical computer storage system includes one or more memory devices that are configured to store digital data associated with software, digital documents, and other resources. For example, a memory device may include a mechanical hard disk drive (HHD), solid-state drive (SSD), such as NAND (Negated AND or NOT AND) flash, random access memory (RAM), read only memory (ROM), or other types of devices. Each type of memory device may be suitable for a particular purpose, performance range, and operational environment.
In general, memory devices are subject to failure, and thus data stored on various memory devices (magnetically, optically, electronically, and so on) may experience various decays. For example, data stored magnetically (e.g., on HDD) may be lost due to magnetic fields decay. Furthermore, data stored by altering material structure (e.g., SSD) may be lost due to further change in its structure. Both HDDs and SSDs may be prone to physical damage, complete and partial failures to some sections. Other issues, such as firmware and software bugs may also cause various issues to data stored on memory devices.
One common solution to alleviate these issues is to duplicate data across redundant disk drives. One such redundant drive approach is facilitated by the Redundant Array of Independent Disks (RAID). Multiple physical disks comprise an array where parity data is added to the original data before storing the data across the array. The parity is calculated such that the failure of one or more disks will not result in the loss of the original data. The original data can be reconstructed from a functioning disk if one or more disks fail. The RAID may use, for example, three or more disks to protect data from failures of any of the disks.
Because the RAID involves replicating data at the storage level, it may propagate errors across multiple copies if the copied data already had errors when copied. Other shortcomings of traditional RAID solution may be associated with editing data in-place, which may cause creating additional errors in the data objects being edited or creating errors in nearby data objects. For example, writing to a SSD device may affect structure of nearby material leading to errors in other data sectors.
Accordingly, there is a need to develop a storage technique that minimizes adverse effects of storage device failures, provides improved efficiency, and enhances protection against data loss.